Dopamine and Reward System

Who has never experienced a sudden craving for chocolate, chips, or dessert, even after a large meal when we are no longer hungry?

This irresistible impulse is not a moral weakness or a lack of discipline, it comes from an ancient and powerful system deeply rooted in our brain: the reward system.

Dopamine is a key neurotransmitter regulating this circuit, and contrary to popular belief, it is not the "pleasure hormone” but acts as a motivational signal. It anticipates pleasure and tells our brain what is worth pursuing, repeating, or seeking. In other words, it reinforces behaviors in which we see value.

This release doesn't occur only when we eat: it can be triggered simply by seeing or smelling food. These signals are enough to activate the reward circuit and create an immediate urge to consume. Once we consume a food, our brain will assess the result, if the food was rewarding (e.g a delicious piece of chocolate), we will learn this behavior was positive and will tend to repeat it.

Those mechanisms serve a survival purpose. In an ancestral environment where resources were scarce and unpredictable, being able to quickly identify, seek out, and consume high-energy foods was crucial. However, we now live in a world where high-calorie, sugary, and fatty foods are abundant, accessible and cheap. On top of that, we’re bombarded by advertisements, app notifications, and colorful packaging, which constantly activate the reward system. In such an environment, those reward seeking mechanisms can lead to overconsumption and in some cases even into forms of food addiction.

The good news: this system is not fixed.

The brain is plastic, meaning it can rewire itself based on experience. It is possible to unlearn certain behaviors and build new ones.

This can be achieved through strategies beyond willpower:

• Change the context and routines to reduce exposure to triggers.

• Gradually reduce the reward frequency to devalue specific behaviors.

• Train to respond differently to the same stimulus (e.g. via inhibition or attention redirection exercises).

• Create new dopaminergic associations with positive, healthy activities.

Take-home message

• Dopamine is a messenger of motivation and anticipation, not of immediate pleasure.

• It drives action when something (like food) appears to have high value.

• In today’s world, the brain is overstimulated, which fuels overconsumption habits.

• These responses are innate but reversible thanks to brain plasticity.

Camille Marchal